Cupola furnace



Oct. 29, '1929. F. A. STEVENSON CUPOLA FURNACE Original Filed June 29, 1928 2 Sheets-Sheet 1 INVENTOR f n'derlck i Stevenson BY 1 5/! '1 I a ATTORNEY Oct. 29, 1929.

F. A. STEVENSON CUPQLA FURNACE Original. Filed June 29, 1928 2 Sheets-Sheet 2 0 wV W \\\\\\&A\\\\\\\\ (V w w w H a M a w, w w w w M w a w MN, \NKE/ MHz/v 4 v a. w y w INVENTOR frederzJ (5722/8/25072 BY E ATI'ORNEY Patented Oct. 29, 1929 ni 's!) STATES PATENT OFF-ICE, Y

FREDERICK A. srnvnnsoiv, OF NEW YoRK, N. iQ AssIGNoR T0 ECONOMY METAL rnonuors CORPORATION, or new YORK, N. Y., A CORPORATION on NEW YORK CUPOLA summon Original application filed June 29, 1928, Serial No. 289,100. Divided and this application filed February This invention relates to cupola furnaces for use in the smelting and reduction of ores generally, and this applicatlon 1s a dIVlSlOIl of my prior application, Serial No. 289,100,

nace above the preheating zone, and thempola of the present invention aims to effect this result by the substitution of a metallic liner for a portion of the-usual refractory lining of the furnace shaft to provide an air heating chamber, whereby'to reduce the tem-' perature in the shaft above the preheating zone to'prevent the absorption of carbon by the CO, to therefore reduce the gas producer effect of the cupola. I am aware of the patent to P. A. Cerieys No. 1,099,737, of June 9, 1914, in which two spaced'metallic rings are shown as a portion of the shaftbut the present invention is distinguished therefrom in that the patentee, Cerieys, contemplates the burning of the CO in the shaft, thus absorbing the carbon and thereby increasing.

the temperature in the furnace shaft above the melting zone. The invention shown herein is distinguished further from thispatent to Cerieys in that fundamentally it is the purpose of the furnace of the present, invention to reduce the temperature in the furnace shaft above the preheating zone and thereby provide a distinct cool zone, or. zone from' which'the heat is transferred to air in the air heating chamber through the metallic liner, thereby permitting the said liner to take up more heat and thus retain the shaft adjacent theliner in a relatively cool condition to prevent the loss of the heat units in the fuel beds while they are in that portion. of the furnace. r

A further object of the invention is the Serial No. 342,901 a provision of cupola, the shaft of which is theoretically divided into three separate and distinct zones of different temperatures; the upper zone being a cool zone, or what may be termed the magazine zone, the middle or intermediate zone, or, to be more exact, the

preheating zone, and the lower or melting zone.

A still further object is the provision of a cupola having means for reducing the temperature in the shaft above the preheating zone whereby to retain the fuel beds therein at a cool temperature, more particularly a temperature such that the maximum number of heat units in the fuel are preserved or retained prior to the delivery'of the fuel to the};

preheating zone of the cupola.

This invention generally contemplates the provision of a metallic liner for a portion of the furnace shaft'to define an air heating chamber having an intermediate sheet or partition therein which is adapted to confine the air whereby it is retained, against the liner to receive heat therefrom, thereby permitting the liner to absorb more heat from the furnace shaft as the heated air is dis;

and more air ad as to aid in preventing such rings from. getting out of round when subjected to expansion and contraction dueto normal operation of the furnace.

Another obj ect'of the invention is to pro nace shaft, which liner is formed of'rings superposed one on the other in such a manner as topermit the easy removal of one or more thereof, should the necessity arise, without dismantling the entire liner. f

Other objects and advantages of this invention will be apparent from the following description-taken in conjunction withthe accompanying drawings in which:

vide a metallic liner for a portion of a fur--- Figure 1 is a sectional view through the upper portion of a furnace embodying the present invention;

Fig. 2 is a sectional view on the line 2-2, Fig. 1;

Fig. 3 is a sectional view on an enlarged scale of a part of the furnace shown in Fig. 1;

Fig. 4 is a sectional View on the line 4-4, Fig. 3; v

Fig. 5 is a sectional view similar to Fig. 3, but showing a modification of the invention,

' and Fig. 6 is a view on the line 66, Fig. 5. Referring now more in detail to the drawings, and specifically to Fig. 1, 2 designates air heating chamber being so formed and arranged as to take heat from the shaft of the furnace above the preheating zone to reduce the temperature in the shaft at this zone,

whereby to preserve the heat units in the fuel at this point. The heated air is then directed to the wind-box of the cupola to be injected through the usual tuyeres into the shaft of the furnace adjacent the melting zone, and, by taking the heat from the shaft of the furnace above the preheating zone,

it will be apparent that the heat units in the gases in the shaft of the furnace at this point are utilized to heat air and that by removingthe heat units, as just indicated, they do not, act on the fuel in this portion of the shaft of the furnace sufficiently to destroy any appreciable number of the heat units inthe fuel beds in this zone; which heat units in the fuel are preserved until the fuel reaches the preheating zone.

To effect the aforesaid result, there is substituted for a portion of the refractory lining, which is usually continuous from the base to thetop of the furnace, a metallic lining, indicated generally in Fig. 1 at A, said lining extending to the upper end of the furnace shaft and forming the inner wall of I an air heating chamber, indicated at B, the outer wall of which isthe sheathing 2 and into which chamber the atmospheric air is admitted through an intake 10 and from which chamber the heated air is directed through an opening 11 into a down-comer 12 into the wind-box (not shown) of the furnace. Referring now to the particular details of construction, in Fig. 1 it can be seen that the outer sheathing may be formed of upper and lower overlapping sections 14 and 16; the latter extending above the upper edge of the refractory lining 8 and having an angle ring 18 secured thereto in any suitable manner as by rivets 19; the leg 20 of said ring resting on the upper edge of the lining 8 and havingan annular recess at its edge. In practice, the ring 18 may be formed of a plurality ofconnected segments, if desired. Obviously, the sheathing may be of one piece if desired. The ring 18 serves to support the liner A in a manner presently to be described. The

liner A is formed of metal of such character as to be capable of withstanding, to the maximum degree, the heat to which said liner is subjected in use without cracking or breaking. Obviously, after continual expansion and contraction, the rings will eventually give way, but the construction of. thepresent furnace provides for the easy replacement of either a burned out or cracked or fractured ring. In the instance shown, the liner is formed of a. plurality of continuous superposed rings 22, 24, 26 and 28, and sealing ring 31 supported on a closure ring 29, said sealing ring extending to a sealing plate 33 arranged just below the charging doors 4, and the closure ring 29 being mounted on angles 35 secured to sheathing 2 and hav-' ing its inner edge supported on ring 28, as shown in Fig. 1. I

The liner rings 22 to28, inclusive, are identical in form and are each provided with supporting flanges 30 and 32, along their j upper and lower edges respectively, the lower flange 32 of the lowermost ring 22 being seated in the annular recess in leg 20 of the I tion, it is to be noted that the diameter of the rings 22 to 31, inclusive, is substantially identical with the diameter of the shaft of the furnace at the refractory lining portion thereof, whereby overhangs or shelves, upon which fuel and ore might collect, are eliminated. The lower flange of ring 24 is seated on the upper flange 30 of ring 22, and, likewise, the ring 24 supports the ring 26 andso.

on. V 1

The furnace shown in the drawings also includes a circumferential partition 34 interposed between the liner A and the outer sheathing 2 and which divides the air chamher into inner and outer chambers 36 and 38, respectively; the'partition 34 having openings 40 formed therein at its lower end to permit the air from the intake 10 to pass into the inner chamber in close proximity to the liner A. The upper edge of the partition on angles 46 secured to the sheathing 2 and the partition respectively, as clearly shown in Fi 8. I

Due to the heat to which the rings are subjected, it has been found necessary to provide a means for retaining the rings in position and to aid in preventing distortion thereof, and, in the construction shown in Fig. 3, the retaining means include a plurality of horizontally arranged rows of blocks 48, which are preferably castings, secured to the partition 34: by suitable fasteners, such as rivets 50; said rows of blocks being arranged at levels such that they are adjacent the meeting flanges 30 and 32 of adjacent rings, and each block comprises an attaching base 52 and a head portion 5% which extends so as to approximatelyengage the meeting flanges of adjacent rings.

The head portions of the blocks are provided with longitudinal recesses which are adapted to receive tapered keys 56 which wedgingly engage adjacent rings at the flanges thereof to retain said rings in their alined superposed relation.

Figs. 5 and 6 disclose a modification, the same embodying fundamentally avariation of the partition structure shown particularly in Figs. 3 and 4. The partition in Figs. 5 and 6 is designated generally at 58, and comprises a plurality of arcuate segments 60, the edges of which are secured'by suitable fasteners 62 to shoulders 64 formed on retainer castings 66, which latter are secured by rivets 68 t0 the sheathing 2; the segments, when arranged as just mentioned, defining the inner and outer air chambers 36 and 38, respectively. The free ends of the castings 66 are forked or bifurcated to define channels 70 which engage over the ribs 72 'of longitudinal retainer strips 74, which latter engage the outer wall of the metallic liner A and more particularly are arranged in such a position as to positively engage against the meeting flanges of the liner rings. a 7

From the above description, it is believed that the construction of the furnace of the present invention will be fully apparent to those skilled in the art. In operation the shaft of the furnace having been charged with alternate layers of ore and fuel and the lower fuel beds having been ignited, air will f enter the heating chamber through the intake 10 and will pass also into the inner chamber 36 where it will be intensely heated by the metallic liner and then pass through the down-comer 12 into the windboX and then into the furnace. The liner rings give heat to the air, thus permitting a continuous transfer of heat from the shaft of the furnace adjacent the liner through the liner to air in the heating chamber, and this retains the adjacent portion of the furnace shaft in a comparatively cool condition, thus preventingthe destruction of the heat units in the shaft adjacent the liner and preserving saidheat units until they reach the preheating zone of the furnace. This, it will be apparent, reduces the gas producer effect of the furnace and aflords a greater ratio of fuel than has heretofore been known. Further, in view of the particular construction of the rings, attention being called to'the fact that they are identical, should the lowermost ring 22 become cracked, broken or'out of round, said ring may be removed from the furnace in any suitable manner, thus permitting the rings above said ring 22 to be lowered'and permit the insertion of a new ringat the upper end of the liner.

of a plurality of'superposed rings, said member being spaced from thesheathing, a parti- 'tion intermediate the metallic member and sheathing to define inner and outer air chambers, and means connected to said partition and engaging the metallic member to retain the latter in position. I i 2. In a cupola furnace, an external sheathing, a shaft, a plurality of similar metallic,

rings formings a part only of the lining and superposed one on the other whereby any one thereof may be removed, said rings being spaced from the sheathing, a partition interposed'between the sheathing and rings to define inner and outer air chambers, and means associated with the partition to retain the rings in superposed alinement.

" 3. In acupola furnace, a sheathing, arefractory lining forming a portion only of the shaft, a sectional metallic liner supported by the refractory lining and defining with the sheathing an air heating chamber, a partition intcrmediate' the sheathing and liner, and

means secured to said partition and engaging the metallic liner for retaining the sections.

thereof in alinement.

4. In a cupola furnace, an outer sheathing,

I a: refractory liningforming a portion only, of

the furnace shaft, a plurality of superposed metallic rings supported by the refractory" lining and defining with the sheathing an air heating chamber extending to the top of the furnace, said rings having annular flanges on their upper and lower edges, a partition intermediate the sheathing and rings, liner retaining means secured to the partition adjacent.

the flanges of said rings, and means cooperating with said retaining means adapted to engage said flanges to retain the rings in vertical alinement.

5. In a furnace having a portion of the shaft thereof formed of superposed metallic rings, means for maintaining said rings in vertical alinement comprising retainers supported adjacent the junction of superposed rings, and means cooperating with said retainers and engaging said rings.

6. In a furnace, a sheathing, a metallic liner formed of a plurality of superposed metallic rings forming a part of the furnace shaft and defining with the sheathing an air receiving chamber to which heat from the adjacent portion of the shaft is transmitted to heat the air in said chamber to reduce the temperature in the shaft, a partition intermediate the sheathing and metallic liner, and means connected with the partition and engaging the rings for maintaining the latter in vertical alinement and for resisting torsional strains.

7 In a cupola furnace, a sheathing, a refractory lining forming a portion only of the furnace shaft, a metallic liner forming the remainder of the furnace shaft and comprising a plurality of superposed rings having annular flanges along their upper and lower edges, said liner defining with the sheathing an air heating chamber adapted to receive heat from the furnace shaft to maintain the adjacent portion of the shaft at a reduced temperature, a liner centering means supported by the refractory lining and on which the liner is mounted, and means engaglng the meeting flanges of superposed rings for maintaining said rings in vertical alinement.

8. In a cupola furnace, a sheathing, a refractory lining forming a portion only of the furnace shaft, a metallic liner forming the remainder of the furnace shaft and comprising a plurality of superposed rings having annular flanges along their upper and lower edges, said liner defining with the sheathing an air heating chamber adapted to receive heat from the furnace shaft to maintain the adjacent portion of the shaft at a reduced temperature, a linercentering means supported by the refractory lining and on which the liner is mounted, a partition intermediate the sheathing and metallic liner for confining air in said chamber against the liner, and means connected to said partition for maintaining the rings in vertical alinement and for resisting torsional strains.

In witness whereof I have hereunto set my hand.

FREDERICK A. STEVENSON. 

